Miniaturized devices to detect analytes in biological samples are known, comprising a light source and a system containing the sample.
For example, the international patent application WO-A-2005/103652 describes a miniaturized device that comprises a light source consisting of an OLED (Organic Light Emitting Diode) system, diffraction filters to direct the light emitted by the light source toward the sample to be analyzed, and other diffraction layers suitable to direct the light emitted by the sample to the detection system. The device described in the application WO-A-2005/103652 provides that the wavelengths of the light emitted by the light source are selected so as to transmit to the sample only the wavelengths concerned in stressing the sample, where said selection is made through the creation of vertical cavities inside the OLED layer.
Another state-of-the art device is described in the international patent application WO-A-2007/097572 which provides not only a light source consisting of a LED (Light Emitting Diode) system but also a layer of material intended to form a stable link with the sample to be analyzed directly applied on the light source. The layer essentially consists of a surface functionalized by means of suitable linker molecules able to fix the analyte molecules stably. The wavelengths of the light emitted by the light source are controlled using a system known as quantum dot.
Another miniaturized device for detecting an analyte in a biological sample is described in the international patent application WO-A-03/060461, which describes in general terms a device comprising a light source, a first system of filters for transmitting the light to the sample and a detector system able to detect the light emitted by the sample, where the light emitted by the sample is directed to the detector system through a second system of filters.
Moreover, the international patent application WO-A-2007/054710 describes a device comprising an OLED source for the emission of light necessary to excite the sample contained in a microfluid system and a detector system located in direct contact with the microfluid system. The device described therein provides that the micro-channels that make up the microfluid system consist of polydimethylsiloxane doped with suitable coloring agents, the function of which is to absorb the wavelengths of light emitted by the OLED source which could interfere with the analysis of the sample and are therefore able to transmit to the sample only the light wavelengths useful to carry out the analysis.
The US patent application US-A-2003/035755 describes a device that has an OLED-type light source on which a microfluid device is positioned, able to contain the sample to be analyzed, and also comprises, in succession, a layer of lenses to focus the light emitted by the sample, a layer defined as pinhole layer and another filter followed by the detector system. The layer of lenses, the pinhole layer and the other filter are components suitable to focus and filter the light emitted by the sample to be analyzed so as to eliminate the wavelengths that could interfere with the analysis.
The international patent application WO-A-2007/107947 describes a micro-electronic device to detect an analyte in a sample, characterized by the presence of heating electrodes and field electrodes. The function of the latter is to induce the movement/flow of the sample inside the device. The heating electrodes are intended to heat the sample and can be coupled with Peltier cells in order to effect thermal cycles of heating and cooling so as to conduct the relative analysis.
The US patent application US 2002/095073, which defines the closest state of the art to the present invention, describes a wide range of bio-chips in which the biological probes are disposed on a transparent substrate, such as glass or plastic, and in which the latter can possibly be inserted in a microfluid circuit for the circulation of the biological fluid examined.
This document describes the possible use of an OLED or LED source under the micro-array of probes deposited on the same slide. The document has problems concerning the sensitivity of detection inasmuch as, since the intensity of an OLED or LED source can be from 100,000 to 1,000 times higher than the intensity emitted by a possible marker, such as for example a fluorophore, this makes it impossible to detect the latter without the appropriate use of particular optical devices, which are not described in U.S. Pat. No. '073.
Although miniaturized devices to detect an analyte in a biological sample have already been described and marketed, there is a continuing need to develop devices that allow to conduct analyses that are increasingly sensitive and specific by operators who are not specialized, that is, not belonging to analysis laboratories, but by medics at the so-called “points of care”, where the analysis must be carried out in real time, in the presence of the patient.
Purpose of the present invention is to provide an improved device that allows to conduct analyses of this type with optimized reaction conditions in order to increase the sensitivity and specificity of the analysis, and also to reduce the times needed to carry out the analysis. In particular, the purpose of the present invention is to perfect a miniaturized device that allows a simultaneous analysis relating to the presence of several pathogens in the biological sample analyzed.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.